Not Applicable.
Not Applicable.
The present invention relates generally to medical systems and methods for monitoring a heart beat. The present invention relates more specifically to medical systems and methods for monitoring first and second heart beats and detecting coincidence.
Medical monitoring devices are becoming increasingly important in the fields of patient diagnosis and care. New technologies give patient caregivers various alternative tools for performing the tasks necessary to address the needs of their patients.
In one example, the heartbeat of a fetus in the womb is monitored during an examination or during birth. The health and well-being of the fetus can be monitored by studying the fetal heartbeat. Transducers are positioned on or near the fetus to monitor the fetal heartbeat and are coupled with wires to a nearby computer for display and/or charting.
However, existing technology relating to transducer design and placement is prone to errors, such as, noise, multipath, and other signal disturbances. One particularly troublesome error is the tendency of the fetal transducer to acquire the heartbeat of the mother instead of the fetus. When the heartbeat of the mother is recorded and displayed as that of the fetus (e.g., on a monitor or strip chart), the caregiver risks an incorrect or inaccurate diagnosis.
Correct positioning of the fetal transducer can avoid the mother""s heartbeat while acquiring the fetal heartbeat. However, it is not easy to identify when the fetal transducer is correctly positioned. One proposed solution is a fetal monitor capable of recording the heart rate traces of a fetus and a mother. The heart rates are traced on a chart and, if the heart rates are coincident, a warning signal is generated. One drawback of this proposed solution is that heart rates from two different sources can vary widely, even crossing one another at times, particularly during childbirth. Furthermore, a threshold must be established around one heart rate signal (e.g., +/xe2x88x925 beats per minute) which, under some conditions, does not precisely identify whether the incorrect heart rate is being monitored.
Accordingly, what is needed is a system and method for detecting heart beat coincidence that avoids the uncertainties associated with heart rate generation and monitoring. Further, what is needed is a system and method that is more precise, and provides improved coincidence detection in a shorter time period. Further still, a system and method is needed that provides a higher degree of certainty in coincidence detection. The system and method would further be more versatile than prior systems.
According to an exemplary embodiment, a method of detecting heart beat coincidence includes receiving first and second signals from first and second heart beat sources. The method further includes detecting first heart beat occurrences on the first signal, each first heart beat occurrence having a respective time associated therewith and detecting second heart beat occurrences on the second signal, each second heart beat occurrence having a respective time associated therewith. The method further includes comparing the times of the first and second heart beat occurrences to detect coincidence.
According to an alternative embodiment, a system for detecting heart beat coincidence includes means for receiving first and second signals from first and second heart beat sources, respectively. The system further includes means for detecting first heart beat occurrences on the first signal, each first heart beat occurrence having a respective time associated therewith and means for detecting second heart beat occurrences on the second signal, each second heart beat occurrence having a respective time associated therewith. The system further includes means for comparing the times of the first and second heart beat occurrences to detect coincidence.
According to another alternative embodiment, a heart beat coincidence detection system includes a processor and an output device. The processor is configured to receive first and second cardiac signals, to detect first and second heart beats on the first and second cardiac signals, respectively, to calculate phase shifts between respective first and second heart beats, and to generate a display signal based on the phase shifts. The output device is configured to receive the display signal and to provide the display signal to an operator.